[Gdal-dev] Does GDAL1.4.1 support vector quantization

[Frank Warmerdam]

Alison Luo wrote:
> Sample NITF file U_3058b.ntf from
> ftp://ftp.remotesensing.org/gdal/data/nitf/nitf2.0/
> has vector quantization compression. The image has 1
> block of size 1536x1536. I used RasterIO method in
> GDALDataset class to get raw image data as follows:
> 
> imgData->RasterIO(GF_READ,0,0,1536,1536,pData,1536,1536,GDT_Byte,1,NULL,0,0,0);
> 
> But the returned data in buffer pData is all wrong. Is
> it because GDAL does not support vector quantization
> compression or I did not use RasterIO correctly?

Alison,

I believe this is a bug in the NITF driver VQ decoding.  The VQ decoder
was intended for a very specific data product (CADRG?) and I suspect the
issue is that this file does not adhere to the particulars of that product.

I'd appreciate it if you could file a bug report in the GDAL trac on this
issue, and I'll try and address it when practical.

Best regards,
-- 
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